XBT Analysis - Brazil Current variability at 34°S
The Brazil Current (BC) is the southward flowing western boundary current closing the circulation of the South Atlantic subtropical gyre. The dynamics in the southwestern Atlantic are dominated by the convergence of the southward and warm flow of the BC with the northward and cold flow of the Malvinas Current (MC).The area of convergence of these two currents, called the Brazil‐Malvinas Confluence, exhibits complex frontal motions and patterns with the simultaneous presence of warm and cold rings and eddies. The importance of investigating the transport variability of the BC front resides in that this current takes waters from subtropical to subpolar regions, and that it has been shown to also be linked to the variability of the Atlantic Meridional Overturning Circulation.
The Brazil Current
Location of the AX18 realizations, which were used to compute the Brazil Current variability at 34°S, overlaid on the (left) Mean Dynamic Topography, and (right) Mean Geostrophic Velocity from the MDT_CNES-CLS09 climatology.
Brazil Current velocity and transport variability (34°S)
(upper-left) Mean baroclinic geostrophic velocity accross 34°S computed using 20 AX18 realizations, and its (upper-right) standard deviation. The southward flow of the Brazil Current is evident to the west of 50°W. The reference level adopted is at 800 m. (lower) Time-series for the integrated volume transport accross 34°S between 53°W and 40°W (1 Sv = 106m3s-1).
The temperature variability accross the Brazil Current front at 34°S can be found here>>
The XBT data along AX18 can be obtained here>>
Goni, G.J., F. Bringas, and P.N. Di Nezio, 2011: Observed Low Frequency Variability of the Brazil Current Front. J. Geophys. Res., 116, C10037, doi:10.1029/2011JC007198. [PDF]
Lentini C., G.J. Goni and D. Olson, 2006: Investigation of Brazil Current rings in the confluence region. J. Geophys. Res., 111(C6):C06013,doi:10.1029/2005JC002988. [PDF]
Goni, G.J. and I. Wainer, 2001: Investigation of the Brazil Current front variability from altimeter data. J. Geophys. Res.,106:31117-31128. [PDF]
Wainer, I., P. Gent, and G.J. Goni, 2000: Annual cycle of the Brazil-Malvinas confluence region in the National Center for Atmospheric Research climate system model. J. Geophys. Res., 05(C11):26,167-26,177.
Boebel O., C. Schmid, G. Podesta, and W. Zenk, 1999: Intermediate water in the Brazil-Malvinas Confluence Zone: A Lagrangian view. J. Geophys. Res., 104(C9):21,063-21,082. [PDF]
The Mean Dynamic Topography and Mean Geostrophic Velocity fields are from the MDT_CNES-CLS09 climatology produced by CLS Space Oceanography Division and distributed by AVISO, with support from CNES.